The paper stated the working principle of the double screw air compressor and introduced the energy waste phenomenon of the conventional air compressor system and the problems existed in the start of the large power air compressor.According to the condition,a centralized control system of the frequency conversion for the air compressor was designed and the general centralized control could be made on the air compressor.According to the actual required air supply,the frequency converter could be applied to the speed control of the air compressor.Thus the problems existed in the large amount available applied conventional air compressors could be well solved,which could provide reference significances to the design of the air compressor and the reconstruction of the conventional air compressor system.